Angiography is a common method used to represent blood vessels based on diagnostic imaging methods, such as X-ray or Magnetic Resonance Tomography (MRT). For an improved representation of the vessels under examination, Digital Subtraction Angiography (DSA) has been developed. DSA is fluoroscopy technique used in interventional radiology to clearly visualize vasculature in a bony or dense soft tissue environment. Images are produced by subtracting a ‘pre-contrast image’ or the mask from subsequent images after the contrast agent has been introduced into a structure or tissue of interest. These images can be used to provide time-resolved or time-varying information that shows the development of the structure or tissue of interest over time.
Repeated intraoperative 3D imaging of a patient's vascular topology during interventional procedures has enabled surgeons to effectively assess the surgical process and better estimate the surgical outcome. Interventional procedures may be made less invasive and the quality increased with the use of such intraoperative 3D imaging. While this repeated intraoperative imaging creates a wealth of image information, it also subjects the patient to increased radiation exposure, when compared to projection imaging. The increased radiation exposure limits the possibilities for repeated intraoperative 3D imaging.